Eskom Uganda Limited being ISO certified embarked on implementing requirements of ISO 14001:2004(E) environment management system standard. One of the environmental requirements is to prevent environmental pollution. For Nalubaale Power Station this implied prevention of any possible release of oil emanating from the turbines, power transformers and other equipment into the surrounding land or water body.
To achieve this, an oil water separation system for the station had to be constructed to clean up the used water of all the oil that would have mixed in during operation from all possible sources of oil contamination in the plant.
Therefore, a technical study of the site was carried out to determine the most economic design, the best layout, specifications for equipment/pipes/sumps etc by Berenyi Incorporated in 2014 on request from Eskom. This technical study resulted into a design proposal which would achieve the following objectives:-
• Prevent release of oil into water or land
• Compliance to NEMA and ISO 14001:2004 requirements
• Prevent health issues that could result from improper handling of waste oils.
• Exceed NEMA requirements of oil discharges of less than 10 mg / L of water discharged into the environment
A contract was therefore signed between SOGEA SATOM and ESKOM to implement the technical design proposal by Berenyi Incorporated. The project covered: - The unit transformer area, Turbine shaft area, Station drain pits, Exterior bulk oil storage tanks, the existing transformer oil water separator, Offsite catchment water area (Njeru side) and Onsite parking drainage areas.
The works involved would include:-
1. Channeling the offsite storm water away from the old transformer oil water separator
2. Channeling away of all storm water from the parking yard from the old oil water separator
3. Providing roofing and adjusting the bund walls on the unit transformers and bulk oil storage tanks.
4. Channeling all top cover pumps outputs from each unit (1-10) into one header pipe to the new oil separator unit constructed beside the old transformer oil water separator
5. Building separator walls in the station drain pits and installing skimmers to clean the water before discharge to the tail race
6. Checking the old transformer oil water separator for soundness of structure and repair the inlet valves